1. Field of the Invention
The present invention relates to a display apparatus, and it particularly relates to a technology for reducing deterioration of an optical element comprised in the display apparatus.
2. Description of the Related Art
Notebook type personal computers and mobile terminals are spreading widely. Today, a liquid crystal display apparatus is mainly used for display apparatus thereof. And an organic EL (Electro Luminescence) display apparatus is expected as a new flat-type display apparatus. As for the liquid crystal display apparatus, the straitness of view angle and the lateness of response speed still remain as subjects. On the other hand, the organic EL display apparatus can achieve high luminosity and high efficiency while conquering the above-mentioned subjects.
As for the organic EL display, however, a change of an optical element with the passage of time, that is, a deterioration of the optical element cannot be avoided because of a characteristic thereof. Therefore, a white balance may collapse or a variation of luminance may be arisen by continuous use, even if the white balance has been adjusted at the time of manufacturing. It is known that the organic EL display has remarkable deterioration of the optical element compared with the liquid crystal display, and it is recognized that it is a big problem for the quality of a product.